Auxiliary air inlet for internal combustion engines



R. CAIRNS 311 ERNAL COMBUSTION ENGINES Oct. 15, 1940.

AUXILIARY AIR INLET FOR INT Filed Dec. 15, 1938 Patented Oct. 15, 1940UNITED STATES PATENT OFFICE AUXILIARY 'AIR INLET FOR INTERNAL COMBUSTIONENGINES The principal ob jects of this invention are to effect amaterial increase in the efficiency of internal combustion 'engines bycreating better combustion, reducing oil Consumption, increasinggasoline mileage and to gene'rally efiect a better performance.

The principal feature of the invention consists in the nove arrangementof an auxiliary air intake valve in an engine cylinder whereby greaterturbulence of the explosive gases in the engine cylinder is achieved andstagnant pockets in the cylinder are obviated so that better ignitionand flame propagation is effected, the intake being directed downwardlyinto the cylinder at a point opposite to the infiow of gas from theintake valve.

In the acoompanying drawing,

Figure 1 is a seotional elevational viewof an engine cylinder showingthe piston in the uppermost position and illustrating the location of myimproved auxiliary air intake valve.

Figure 2 is a sectional View similar to Figure 1 showing the enginepiston moved downwardly with the intake and auxiliary valves open andillustrating the manner of flow of the gases.

Figure 3 is an enlarged elevational view of my improved valve.

Figure 4 is an enlarged longitudinal sectional detail of my improvedvalve.

It is commonly known among engineers conversant with the operation ofinternal combustion engines that the percentage of power units presentin the regulation motor fuels is only partly converted into usefulpower. Numerous proposals have been made to provide engine cylinderswith fuel intake valves and separate air intakes, but the presentinvention proposes a novel construction and arrangement .which hasproduced exceptional results.

In the Construction herein shown the cylinder l in which a piston 2operates is closed by a head 3, which is preferably of the "Ricardo"type, directs the combustible mixture past the intake valve 4 across thetop end of the pisten so that the stream of combustible gas flows inunder the head to the side of the piston farthest from the intake.

An opening 5 is preferably arranged to extend vertically through thehead 3 at the side of the cylinder farthest from the intake passageleading from the intake valve, and in this opening is arranged a valvebody- 6 which is threaded externally to fit into the threaded wall ofthe opening, and has a central vertical passage 'I extending upwardlyfrom the bottom end and communicating with a cross passage 8 whichextends out through the side wall of the valve body.

The inner end of ,the vertical passage 'I is formed with a valve seat 9.A valve o of conical formation is adaped to engage and seal against thevalve seat 9 and has a stem l l extend ing upwardly through the top ofthe valve body and the upper end !2 thereof is threaded and has arrangedthereon an adjusting nut l3 and` a lock nut M.

A spiral compression spring l5 encircles the valve stern and engagingthe nut at the top thereof, holds the valve against its seat. These nutsmay be adjusted to vary the tension of the spring so that the valve willopen upon a predetermined vacuum condition within the cylinder,

and'upon opening a stream of air will flow in through the passages 8and] and ibe projected downwardly into the cylinder. The stream of airthus projected downwardly will meet with a p stream of combustible gasflowing across the inner end of the top of the cylinder following thedownward movement of the piston, and mingling with this stream of gas,it will augment the flow thereof and greatly magnify the turbulence ofthe inflowing mixture, thereby preventing the stagnation of the productsof combustion of a previous charge or of the fresh charge of combustiblegas.

By arranging this automatic intake valve in' the position described itassists materially in scavenging the cylinder of burnt gases and asstated, greatly increases the turbulence, and it also increases theVolume of combustible mixture.

in the cylinder which is necessarily restricted by the ordinary intakevalve in its Very brief and rapid period of movement.

In Figure 1 the valve body is shown directly threaded into the openingin the cylinder head and in Figures 3 and 4 the valve has threaded onits lower threaded end an adapter IB which is merely a threaded plug tobe Secured in the threaded opening of the oylinder head, the valve beingthreaded into the interior of the adapter.

Very extensive tests have been made of this device over a period ofapproximately two years and a mileage of approximately twenty-fourthousand mi1es, and it has been ascertained that a very materialreduction in' the consumption of motor fuel is effected. Further it isfound that the use of the device creates a very marked reduction in theconsumption of lubricating oil.

It is also found that with the use of suchan auxiliary air inlet to thecylinders a much more accentuated braking eflect through the medium ofthe engine may be obtained and a smooth powerful braking action isefiected due to the valve taking in air When the throttle is closed.

When the engine is used in this manner it will be apparent that thecombustion space will be effectively scavenged of burnt gases andcooled. This also eects a Very marked increase in acceleration when thethrottle is again opened.

It will be read'ly apparent that having these valves in the cylinder torelieve the suction eiect when the throttle is closed and the engine isidling or Operating at slow speed in traffic, a. great saving in uel iseffected.

A further advantage found in the use of this device is the absence of asmoky and odorous exhaust.

It will be readily understood that this inven tion may be applied toengines which are at present in use as well as to new engines as greateconomy and better performance will be obtained.

It will be noted that the valve body adaptor IS has a valve chamber 16'which converges downwardly to a passage I 6", the cross section of whichis accurately proportioned in relation to the piston displacement and inthe'event of the tension of the spring !5 being too` Weak as forinstance through faulty adjustment or fatigue, the restricted orificewill guard against an excessive Volume of air being drawn into thecylinder.

Further should, for any reason, the valve become detached from thesupporting spring, the

constriction of the valve chamber will prevent same from falling intothe cylinder to cause damage.

What I claim as my invention is:

1. In an internal combustion engine having a cylinder and a fuel intakevalve at one side of the cylinder and a spring-loaded valve foradmitting air to said cylinder on the suction stroke of.` the piston,the combination being characterized in that the air valve inlet ispositioned on the side of the cylinder farthest from the side on whichthe said fuel intake valve is located to direct the incoming airdownwardly along the said farthest side of the cylinder and therebyenhanc'e-turbulence of the incoming fuel charge and minimize pocketingthereof.

2. An internal .combuston engine as claimed in claim 1 in which theengine is provided with a "Ricardo" type head forming with the head ofthe piston a chamber of progressively decreasing depth 'from the fuelinlet valve to the point of location of the said air inlet valve.

3. An internal combustion engine having in combination a verticalopening through the head arranged adjacent to the inner cylinder wall atthe side of the cylinder farthest from the intake leading from thecarburetor, a valve body threaded into the upper end of said verticalopening having a discharge passage arranged to concentratea stream ofair in a. downward direction alongthe side of the cylinder farthest fromthe fuel intake,` and valve means controlling the flow of air throughsaid discharge passage.

ROBERT CAIRNS.

